[FLINK-15566] Flink implicitly order the fields in PojoTypeInfo

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Component/s: Table SQL / API
• Labels: stale-major
• Assignee: Unassigned
• Reporter: Jeff Zhang
• Created: 13/Jan/20 08:03
• Updated: 29/Apr/21 16:47
• Resolved: 29/Apr/21 16:47

Description

I don't know why flink would do that, but this cause my user defined function behavior incorrectly if I and pojo in my udf and override getResultType

https://github.com/apache/flink/blob/master/flink-core/src/main/java/org/apache/flink/api/java/typeutils/PojoTypeInfo.java#L85

 

Here's the udf I define.

 

%flink
import org.apache.flink.api.java.typeutils.RowTypeInfo
import org.apache.flink.api.common.typeinfo.Types
import org.apache.flink.api.java.typeutils._
import org.apache.flink.api.scala.typeutils._
import org.apache.flink.api.scala._

class Person(val age:Int, val job: String, val marital: String, val education: String, val default: String, val balance: String, val housing: String, val loan: String, val contact: String, val day: String, val month: String, val duration: Int, val campaign: Int, val pdays: Int, val previous: Int, val poutcome: String, val y: String)

class ParseFunction extends TableFunction[Person] {
  def eval(line: String) {
    val tokens = line.split(";")
    // parse the line
    if (!line.startsWith("\"age\"")) {
      collect(new Person(new Integer(tokens(0).toInt), normalize(tokens(1)), normalize(tokens(2)), normalize(tokens(3)), normalize(tokens(4)), normalize(tokens(5)), normalize(tokens(6)), normalize(tokens(7)), normalize(tokens(8)), normalize(tokens(9)), normalize(tokens(10)), new Integer(tokens(11).toInt),  new Integer(tokens(12).toInt),  
           new Integer(tokens(13).toInt), new Integer(tokens(14).toInt),  normalize(tokens(15)), normalize(tokens(16))))
    }
  }
  
  override def getResultType() = {
    val cls = classOf[Person]
    new PojoTypeInfo[Person](classOf[Person], java.util.Arrays.asList(
       new PojoField(cls.getDeclaredField("age"), Types.INT),
       new PojoField(cls.getDeclaredField("job"), Types.STRING),
       new PojoField(cls.getDeclaredField("marital"), Types.STRING),
       new PojoField(cls.getDeclaredField("education"), Types.STRING),
       new PojoField(cls.getDeclaredField("default"), Types.STRING),
       new PojoField(cls.getDeclaredField("balance"), Types.STRING), 
       new PojoField(cls.getDeclaredField("housing"), Types.STRING), 
       new PojoField(cls.getDeclaredField("loan"), Types.STRING), 
       new PojoField(cls.getDeclaredField("contact"), Types.STRING), 
       new PojoField(cls.getDeclaredField("day"), Types.STRING), 
       new PojoField(cls.getDeclaredField("month"), Types.STRING), 
       new PojoField(cls.getDeclaredField("duration"), Types.INT),
       new PojoField(cls.getDeclaredField("campaign"), Types.INT),
       new PojoField(cls.getDeclaredField("pdays"), Types.INT),
       new PojoField(cls.getDeclaredField("previous"), Types.INT),
       new PojoField(cls.getDeclaredField("poutcome"), Types.STRING),
       new PojoField(cls.getDeclaredField("y"), Types.STRING)
     ))
  }  

  // remove the quote
  private def normalize(token: String) = {
      if (token.startsWith("\"")) {
          token.substring(1, token.length - 1)
      } else {
          token
      }
  }
}

And then I use this udf in sql but get the wrong result because flink reorder the fields implicitly.